Intermittent fluid flow control mechanism



Feb. 28, 19 D. A. M DONALD 2,736,297

INTERMITTENT FLUID FLOW CONTROL MECHANISM Filed July 5, 1953 I 5 Sheets-Sheet l .00/70/0 A. Mac 170/70/0 INVENTOR.

ATTOR/Vfy Feb. 28, 1956 D. A. Ma DONALD 2,736,297

INTERMITTENT FLUID FLOW CONTROL MECHANISM Filed July 3, 1955 I: Sheets-0118GT, 2

.[70/70/0 A. Macflona/o INVENTOR.

ATTORNEY Feb. 28. 1956 D. A. MacDONALD 2,736,297

INTERMITTENT FLUID FLOW CONTROL MECHANISM Filed July 5, 1955 s Sheets-Sheet s Dona/0 A. Mac flono/a/ INVENTOR.

ATTORNEY United States atent INTERMITTENT FLUID FLOW CONTROL MECHANISM Donald A. MacDonald, Houston, Tex.

Application July 3, 1953, Serial No. 366,001

4 Claims; (Cl. 121-150) This invention relates to intermittent fluid-flow control mechanism, and-more particularly to mechanism for controlling the intermittent flow of pressure fluid to pressure operated apparatus and the return of such fluid to a storage reservoir.

The invention finds particular application in connectionwith the operation of well pumping mechanism of the type disclosed in prior pending application Serial No. 765,905, filed August 4, 1947, by the same applicant, and now Patent No. 2,650,574, issued September 1, 1953.

An important object of the invention is to provide means for applying fluid pressure to, and relieving said pressure from pressure operable apparatus to effect operation thereof.

Another object of the invention is the provision of mechanism intermittently for applying fluid under pressure to pressure operated apparatus and returning the fluid to a storage. reservoir during the intervals between the application of the fluid to such apparatus.

A. further object of the invention is to provide a pressure fluid system for intermittently supplying fluid under pressure; to pressure operated apparatus which system is completely closed and in which pressure fluid is returned toarstorage-reservoir during the intervals between the application ofv thefluid to such apparatus.

A still further object of the invention is the provision of control valve mechanism by which the intermittent application to and relief of fluid pressure. from pressure operated apparatus may be accurately and automatically controlled.

Other important objects and advantages of the invention will be apparent from, the following detailed, description, constituting a specification of; the same when con sidered in conjunction with the annexed drawings,,wherelIL- Figure 1 is a side elevational view partly in cross-sectionillustrating the details of construction and arrange.- ment: of. theparts of the invention and showing the posi-- tions occupied by the various parts during the application ofrthe. pressure fluid to the pressure, operated apparatus;

Figure 2. is a view similar to that of Figure I wherein the positions occupied by the parts at an intermediate stage of the operation of the mechanism is shown; and

Figure 3, is: aview similar to that of Figure 1 wherein the. positions, occupied by the various parts during; the relief oi the pressure fluid from the pressureoperated apparatus is. shown.

The invention, is adapted for use in connection with. fluidpressureapparatus such, for example, as pumps and the. like, whichare operatable by the intermittent applicationof pressure fl'uid, and while not limited tosuch use, finds particular application in connection with fluid lift pumping equipment of the type described in. said prior, pending application.

Referring-now to the drawings in greater detail, where in likereference' characters are employed to designate thesame parts-throughout the several views',"the'numeral designates a pressure fluid supply conduit leading to one or more pressure operable devices of suitable character adapted to be operated by the intermittent application and release of" fluid pressure, such as a fluid lift pump, not shown, located in a well, such as an oil well, and which maybe of the type disclosed insaid prior pending application, or otherwise. This supply conduit is connected in communication with the discharge outlet of a fluid pressure pump 12, through a pipe 14 and branch pipe 15, through which the flow of fluid is controlled by control valve mechanism generally designated 16, and the pump receives its supply of fluid through a pipe 18 connected to the inlet of the pump and to a fluid reservoir indicated at 20.

A return pipe or surge line 22 is also connected in communication with thefluid supply conduit 10, which return pipe leads to return valve mechanism generally indicated at 24, which in turn is, connected in communication with the supply reservoir 20 by a pipe 26.

The pump 12 may bev of any suitable type and is adapted to be driven from a source of power by conventional means not shown.

The discharge line 14 of the pump is also connected by abranch pipe 28, to the control valve mechanism 16, from which a pipe 30 leads to the return valve mechanism 24 from which a pipe 32 leads to the reservoir 20. By'suitable' operation of the control valve 16 and return valve' 24, it will be seen that fluid under pressure from the pump may be intermittently applied through the pipe 10 to the pressure fluid. operated apparatus, and returned therefrom through the surge line 22 to thev reservoir, and during such return of the pressure fluid, the discharge from the pump will return to the reservoir through the pipes 28, 30 and 32. Thus the pump 12 may be continuously operated to secure the intermittent application of pressure fluid to the pressure fluid operated apparatus.

A suitable relief or safety valve 34 is connected to the pipe 14 and to the reservoir 29 whereby any accidental increase in pressure in the discharge line of the pump will be prevented. from damaging the mechanism. The pipe 14 also has a branch pipe 36 leading to an air chamber device 38 whose inlet is controlled by a valve 40 under the influence of a spring 42 which urges the valve toward closed position, whereby pressure surges in the discharge line of the pump. are absorbed or cushioned.

Thereturn or surge pipe 22. is connected in communication with the supply conduit 10 through a check valve device 44 wherein a valve 46 is urged toward closed position against the pressure in the supply conduit by a spring 48.

The control valve mechanism 16 may take the form of a cylindrical casing 50 whose opposite ends are closed by screw plugs 52 and 54, respectively, the plug 52 having a pipe 56 connected thereto in communication with the interior of the casing and leading to the surge pipe 22, and the plug 54 having a pipe 58 connected thereto in communication with the interior of the casing and leading to a pipe 60, which communicates with pipe 30 and is connected to the control valve mechanism.

Within the casing 50 a valve core 62 is disposed for longitudinal movement, which core is provided with external annular grooves 64, 66, 68 and 70. In the position of the core 62 illustrated in Figure l the groove 7 is in communication with pipe 10 and branch pipe 15, so that fluid may flow from the pump 12 through pipe 10 to the pressure fluid operated apparatus, and groove 70 is in communication with pipe and with a pipe 72 leading to the reservoir 20, so that fluid may flow from pipe 30 and from pipe 58 to the reservoir.

When the valve core 62 is in the position seen in Figures 2 and 3, the groove 64 is in communication with pipes 28 and 30, While groove 66" is in communication with a branch pipe-74 leading from pipe- 10 and with a pipe 76 leading to the lower end of the return valve mechanism 24.

The valve core 62 has the counterbores 78 and 80 in its opposite ends, in which coil springs 82 and 84, respectively are disposed, and is also provided with inwardly extending, annular projections 86 and 88, at its opposite ends forming parts of latching mechanism, later to be described in detail. Longitudinally movable pistons 91) and 92 are also positioned within the opposite ends of the valve casing 50, which pistons have plungers 94 and 96, respectively, which work in the respective counterbores 78 and 80, to engage the springs 82 and 84', respectively, upon inward movement of the pistons. Coiled springs 98 and 1%, respectively, are positioned in the casing 50 in engagement with the pistons W1 and 92 and with internal annular flanges 162 and 104, respectively, to urge the pistons outwardly toward the ends of the casing.

Latch elements 166 and 188, respectively are pivotally mounted on the flanges 182 and 164, the latch element 186 being engageable with the annular projection 86 to hold the core 62 against movement in one direction, while the element 168 is engageable with the annular projection 88 to hold the core against movement in the opposite direction. Each of the latch elements has a coiled spring 111 which urges the element toward a position to 'latchingly engage the respective projection. The latch elements are engageable with shouldered portions 112 on the pistons 90 and 92 upon inward movement of the pistons to move the elements to unlatching positions.

The return valve mechanism 24 comprises a return valve casing 114 and an escape valve casing 116 disposed in longitudinal alignment. The return valve casing 114 is closed at its upper end by a plug 118, having an inwardly projecting stop lug 121! thereon within the casing, and at its lower end by a cap 122 which has a central tubular extension 124 projecting through a central opening in a cap 126 which closes the upper end of the escape valve casing. The lower end of "the escape valve casing is also closed by a cap 128 with which the pipe 76 is connected in communication with the interior of the escape valve casing.

Within the return valve casing a valve core 136 is positioned for longitudinal movement, which core has external annular grooves 132, 134 and 136. A coil spring 131 bears at one end against the upper end of the core 136 and at its other end against the plug 118 to urge the core downwardly in the return valve casing. When the core 130 is in the position seen in Figure 2 the grooves 132, 134 and 136 are in communication, respectively, with pipes 138, 32 and 26 which lead to the reservoir 20 and connect these pipes in communication with pipes 14-6, 30 and 22 respectively. When the core 136 is in the position shown in Figures 1 and 3, however, the pipes 148, 35 and 22 are cut oil? from communication with the reservoir.

The return valve casing is also formed with an internally thickened annular portion 142, through which guide openings 144 and 14-6 extend in which latch operating members 148 and 158, respectively, are slideably extended.

The core 136 is formed with a downwardly extending reduced portion 152 having longitudinally spaced external annular grooves 154 and 156 therein. A piston 158 is disposed within the lower end of the return Valve casing for longitudinal movement therein, which piston has an upwardly opening counterbore 169 and a downwardly projecting stem 162, which projects through the tubular extension 124 of the cap 122 into the escape valve casing 116 and is connected to a plate 164 slideably disposed in the casing 116 and having perforations 166 therethrough. Within the counterbore 168 there is a coiled spring 168 which bears at one end on the lower end of the reduced portion 152 of the core 139 and is seated at its other end on the bottom of the counterbore. A coiled spring 176 is also disposed in the escape valve casing 116 in engagement with the plate 164 therein and with the inside of the cap 126 to urge the plate downwardly in the casing.

Piston 158 has a skirt 172 to which the latch operating 4 members 148 and 156 are fastened to move with the piston, and the member 148 has an upwardly-facing sloping latch engaging surface 174, while the member 150 is provided with a similar downwardly-facing sloping latch engaging surface 176. Oppositely disposed latches 178 and 18d, extend into the return valve casing in position to engage in the grooves 154 and 156, respectively to latch the core 136 in either of its extreme positions in the casing, and each of these latches is slideable in a housing 182 mounted on the exterior of the casing 114 and is urged inwardly by a coiled spring 184 located in the respective housing. Each of the latches has an opening 186 therethrough through which the respective operating member extends and is provided with a sloping surface 188 for engagement with the sloping surface of the respective operating member to move the latches outwardly to their unlatching positions upon longitudinal movement of the operating members. it will be noted that upon upward movement of the piston 158 the latch operating member will engage and move the latch 178 outwardly to disengage the latch from the groove 154 whereby the core 136 is released to move upwardly to the position seen in Figure 1, and in that position the latch 18% will enter the groove 156, while upon downward movement of piston 158 the latch operating member 15% engages latch 180 to move the same out of groove 156 to release the core 130 to move downwardly to the position seen in Figures 2 and 3, whereupon latch 178 enters groove 154 to lock the core in down position.

The pipe 146 is connected in communication with the interior of the escape valve casing 116 at a location such that the plate 164 cuts off flow therethrough when the piston 158 is in its uppermost position, and also has a branch pipe 198 leading into the lower part of the return valve casing at a point such that fluid flow through this pipe will be cut off by piston 158 when in its lowermost position, as seen in Figures 1 and 2.

In the operation of the mechanism, when the parts are in positions illustrated in Figure 1, pressure fluid from reservoir 26 flows through pipe 18 to pump 12 and is pumped therefrom through pipes 14, 15 and groove 68 to pipe 11 whence it flows to the pressure fluid operated apparatus. During such supply of fluid to the pressure fluid operated apparatus the valve 46 is closed core 62 is latched in the position seen in Figure 1, and core 130 is in its downmost position wherein it is latched by latch 178.

When the pressure fluid operated apparatus, which may be a pump of the piston type, reaches the end of its stroke, there is a sudden increase in pressure in the supply pipe 10 which causes valve 46 to open, admitting fluid to pipe 22, whereupon fluid flows through branch pipe 56 into the casing 50 to move piston to the right. By this movement the shoulder 112 of piston 90 engages latch 106 and releases the core 62 which is then moved to the right by engagement of the plunger 94 with spring 82, until the internal annular projection 88 is engaged by latch 108 to lock the core in the position seen in Figures 2 and 3. In this position of the core 62, fluid from pipe 10 may flow through pipe 74, groove 66 and pipe 76 into the lower end of the escape valve casing 116 beneath plate 164 to move the plate upwardly, thus moving piston 158 upwardly to cause member 148 to move latch 178 to unlatching position, whereupon the core is moved upwardly by spring 168 to the position seen in Figure 3, to permit fluid to flow through pipe 22, groove 136 and pipe 26 to reservoir 26. When the core 130 reaches its uppermost position the latch enters groove 154 to retain the core in this position. Because of the perforations 166 in plate 164, fluid from pipe 76 has a restricted flow through pipe 140, groove 132 and pipe 32 to reservoir 20, which flow is cut off when the plate reaches its upper position as seen in Figure 3. Fluid from pipe 76 may also flow through the tubular extension 124 of a cap 122 about the stem 162, from the escape valve casing 116 into the return valve casing, and when the piston 158 has moved upwardly this fluid may also flow through branch pipe 190 into pipe 140 and return to the reservoir.

With the parts in the positions illustrated in Figure 3, fluid from pump 12 may also pass through pipes 14 and 28, groove 64 and pipe 30 back to the reservoir, so that the supply of pressure fluid in pipe is relieved during the return flow from the pressure fluid operated apparatus.

Upon completion of the return flow the valve 46 immediately closes, and because of the fact that fluid may flow from the pump 12 through pipes 14 and 28, groove 64, pipe 30, pipe 60 and branch 58 into the right end of the control valve casing 50, the piston 92 will move to the left unlatching the latch 108 and moving the core 62 to the left to the position shown in Figure 1. In such position of the core 62 the flow of fluid to the escape valve casing and to the return valve casing beneath piston 158 is cut ofl, so that the piston 158 returns to its down position releasing latch 188 from groove 156, and the core 130 is returned to the down position by the spring 131, in which position it is latched by the latch 178 extending into groove 154. The mechanism is then again in the condition illustrated in Figure 1 and fluid is supplied by pump 12 through conduit 10 to the pressure fluid operated apparatus.

It will be apparent that the movements of the control valve mechanism and return valve mechanism are very rapid, the cores 62 and 130 moving immediately from one extreme position to the other at the completion of each cycle of the pressure fluid operated apparatus, and that the operation of the valve mechanism takes place entirely automatically in accordance with the changes in pressure in the system.

It will thus be seen that the invention, as described above provides intermittent fluid flow control mechanism which is fully automatic and positive in operation, and which has means whereby premature accidental actuation of the valves is prevented.

The invention has been described in connection with a certain specific embodiment of the same, but it will be understood that this is intended by way of illustration only, and that numerous changes can be made in the construction and arrangement of the various parts, without departing from the spirit of the invention or the scope of the appended claims.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent is:

1. Control valve mechanism for controlling the intermittent application of fluid under pressure to and relieving the pressure from pressure fluid operated apparatus comprising a valve casing, a valve body movable in the casing to one position to permit the flow of pressure fluid to said apparatus and to another position to cut ofl said flow, latch means in said casing movable into engagement with said body to hold the body in said positions and out of engagement with the body to release the body, and means operable by the pressure of said fluid upon a predetermined change in said pressure to move said latch means out of engagement with the body and move said body from one to the other of said positions.

2. Control valve mechanism for controlling the intermittent application of fluid under pressure to and relieving the pressure from pressure fluid operated apparatus comprising a valve casing, a valve body movable in the casing to an open position to permit the flow of pressure fluid to said apparatus and to a closed position to cut off said flow, latch means in the casing movable into engagement with said body to hold the body in said open and in said closed position and out of engagement with the body to release the body, and means operable by the pressure of said fluid upon a predetermined change in said pressure to release said latch means and move said body from one to the other of said positions.

3. Valve mechanism for controlling the intermittent application of fluid under pressure to and relieving the pressure from pressure fluid operated apparatus comprising, a supply conduit connected in communication with pressure fluid operated apparatus, means for taking fluid from a source of operating fluid and supplying it under pressure to said supply conduit, 21 return conduit connected in communication with the supply conduit and with said source, a return valve in said return conduit movable to an open position to permit the flow of fluid from said supply conduit to said source and to a closed position to cut off such flow, latch means engageable with said control valve to hold the return valve in each of said positions, latch release means operable by the pressure of fluid in said supply conduit when said pressure exceeds a predetermined limit to release said latch means to permit said return valve to move from said closed to said open position and to thereafter move said return valve to said open position, said release means being also operable upon a reduction in said pressure to release said latch means to permit said return valve to move from said open to said closed position, and means urging said return valve toward said closed position.

4. Valve mechanism for controlling the intermittent application of fluid under pressure to and relieving the pressure from pressure fluid operated apparatus comprising, a supply conduit connected in communication with pressure fluid operated apparatus, means for taking fluid from a source of operating fluid and supplying it under pressure to said supply conduit, a return conduit connected in communication with said supply conduit and with said source, a return valve in said return conduit movable to an open position to permit the flow of fluid from said supply conduit to said source and to a closed position to cut off such flow, latch means engageable with said return valve to hold the return valve in each of said positions, means urging said return valve toward said closed position, latch releasing means operable in one direction to release said latch means and to move said return valve to open position and in the other direction to release the latch means to permit said return valve to move toward closed position, and means operable by the pressure of fluid in said supply conduit upon an increase in said pressure beyond a predetermined limit to move said latch means in said one direction.

References Cited in the file of this patent UNITED STATES PATENTS 2,029,145 Wilson et a1 Jan. 28, 1936 2,298,457 Berges Oct. 13, 1942 2,302,232 MacNeil Nov. 17, 1942 2,550,723 Ross May 1, 1951 2,650,574 MacDonald Sept. 1, 1953 

